NAME
m.examine.tape - Provides a description of the
files on a 1/2-inch magnetic tape.
(GRASS File Management Tool)
SYNOPSIS
m.examine.tape
DESCRIPTION
m.examine.tape is a convenient tool for previewing
a tape and obtaining block size values. After the user
enters the command
-
m.examine.tape
the program will prompt the user for the full path name of
the tape device on which the tape is mounted. In most
cases, this will be /dev/rmt0. However, the
user must enter this, as there is no default value for the
tape device name. The user is then prompted to enter the
buffer size to be used when reading the tape. The buffer
size is the amount of memory allocated to read one physical
record of the tape. If the user hits RETURN, the program
will assume a default buffer size of 32767 bytes.
m.examine.tape reads the tape specified by the
user and reports back the block size (record length) and
the number of blocks for each file contained on the tape.
m.examine.tape can be used on any 1/2-inch
magnetic tape. The user has the option of sending the
output into a file or viewing the output on the terminal
screen.
NOTES
The buffer size is the amount of memory allocated to read
one physical record on the tape. Magnetic tape devices
will accept a request to read more bytes than actually
exist in any given record on a tape. However,
m.examine.tape reads only as many bytes as
physically exist on the tape and returns the number of
bytes actually read. The user is allowed to alter the
buffer size in order to request smaller reads for tape
devices unable to handle requests this large (32767 bytes),
or to request larger reads for tapes with larger record
sizes read on drives able to handle larger record sizes.
Note that m.examine.tape cannot be used to examine
the content of either ordinary files or 1/4-inch tape
cartridges.
SEE ALSO
m.dem.examine
m.dem.extract
m.dmaUSGSread
m.dted.examine
m.dted.extract
m.lulc.USGS
m.lulc.read
AUTHOR
Michael Shapiro, U.S.Army Construction Engineering
Research Laboratory
Last changed: $Date$